058 FXUS62 KCHS 201745 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 145 PM EDT Mon Apr 20 2020 .SYNOPSIS... A warm front will lift north through the area early this morning followed by a cold front later this morning. High pressure will then slowly build in through Wednesday before another storm system impacts the area Thursday and Thursday night. Unsettled weather could then return over the weekend. && .NEAR TERM /THROUGH TONIGHT/... Early this afternoon: No real change to the forecast. We did include a small area of 20-30 percent rain chances for the next couple of hours across the Tri-County region to account for light showers that developed. Any rain should be brief. Otherwise, scattered cumulus will persist across the area. Temperatures are on track, warming into the low to mid 70s in southeast South Carolina and mid to upper 70s in southeast Georgia. Late this morning: Scattered showers developed along the cold front a few hours ago but have now either dissipated or moved offshore. The rest of the day should be dry, though we could see a stray shower rotate through in the post-frontal airmass. The cold front is situated right across the forecast area, and we are seeing inland sites turn more northwest with time and become gusty. We will maintain breezy conditions through the afternoon hours. Clouds have scattered out across most of the area, and visible satellite imagery shows additional upstream clouds spreading in from the northwest. We will continue to see these cumulus and stratocumulus, with periods of sun mixed. Highs are forecast to range in the low to mid 70s in most areas, with some upper 70s south of I-16 in southeast Georgia. Tonight: High pressure will build across the region this evening and overnight. Winds should become light during the evening, then light to calm tonight. Low temperatures are forecast to fall into the mid 50s to around 60. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... High confidence this period. Deep troughing will linger across the area Tuesday with a dry cold front to move through Tuesday night. High pressure will then move in for Wednesday before quickly shifting offshore Wednesday night as another storm system approaches from the west. There could be a few showers Wednesday night due to warm advection and shortwave energy aloft, but the surface warm front will likely not push north through the area until later Thursday morning as low-level jetting ramps up ahead of the developing surface low over the TN Valley. Surface winds even outside any storms could be rather strong. Deep moisture and strong upper forcing should support a good rain event with several inches possible along with at least a slight chance of severe storms Thursday afternoon into the evening due to plentiful deep and low- level shear and modest instability. Near to above normal temperatures are expected except for Wednesday when it should be below normal. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Moderate confidence Thursday night with low confidence thereafter. Expect the potential for some severe storms into Thursday evening before a cold front pushes through. Weak high pressure should prevail with dry weather Friday but the forecast gets more complicated thereafter given several disturbances in the fast upper flow that could impact the area through the weekend. Temperatures should be above normal until possibly falling back below normal early next week. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... VFR conditions will prevail through 18z Tuesday. A scattered to broken VFR cumulus and stratocumulus deck will continue to move across the terminals. Can't completely rule out a brief period of MVFR ceilings, but chances are low. North west winds will continue to gust into the 25-30 knot range for the next few hours, then diminish in the late afternoon. Extended Aviation Outlook: Restrictions likely return as early as late Wednesday night but most likely Thursday and Thursday night as another storm system impacts the area with strong winds and possible severe storms. VFR should return Friday but more restrictions are possible Saturday as a cold front could impact the area. && .MARINE... This afternoon and tonight: Gale Warnings will expire at 2 pm and have been replaced by Small Craft Advisories either through the afternoon or evening. Currently, the strongest winds are occurring in the Charleston Harbor where the Weatherflow sites at Shutes Folly and Fort Sumter have been gusting to around 33-34 knots. Conditions will improve notably this evening as winds weaken. Tonight, ridging high pressure will yield light winds and seas of 2-3 ft. Tuesday through Saturday: Moderate to high confidence this period. There are no significant concerns through Wednesday night, although conditions could reach marginal Small Craft Advisory levels Tuesday afternoon along the Charleston County coast as the gradient pinches ahead of an approaching cold front. A better chance for Small Craft Advisory/possible Gale conditions are expected Thursday into Friday as yet another potent storm system affects the area. Low confidence of more SCA conditions Saturday depending on whether another cold front impacts the area. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...Small Craft Advisory until 5 PM EDT this afternoon for AMZ330- 352-354. Small Craft Advisory until 8 PM EDT this evening for AMZ350- 374. && $$ NEAR TERM...BSH/NED SHORT TERM...RJB LONG TERM...RJB AVIATION...BSH/RJB MARINE...BSH/RJB